Duplex steam-pump.



PATENTED APR. 4, 1905.

G. A. SNIDBR.

DUPLEX STEAM PUMP.

APPLICATION FILED JUNE 20 1904.

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C. A. SNIDER.

DUPLEX STEAM PUMP.

APPLICATION FILED JUNE 20. 1904.

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DUPLEX STEAM PUMP;

APPLICATION FILED JUNE 20. 1904.

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UNITED STATES Patented April 4, 1905.

PATENT OFFICE.

CLARENCE A. SNIDER, OF CLEVELAND, OHIO, ASSIGNOR TO THE SNIDER- HUGHES COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

DUPLEX STEAM-PUMP.

SPECIFICATION forming part of Letters Patent No. 786,467, dated April 4, 1905.

v Application filed June 20, 1904. Serial No. 213,236.

To all w/wm it may concern:

Be it known that I, CLARENCE A. SNIDER, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Duplex Steam Pumps, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

I The object of the invention is to produce a duplex steam-pump which shall be simpler and cheaper and less liable to'get out of order than any of the duplex steam-pumps now in use, but which shall be no less efficient.

The invention relates to the steam-cylinders and their associated parts, which operate the water-pump pistons.

In pumps embodying my invention there is no steam-chest distinct from the cylinders and no valve-operating mechanism outside of the cylinders or movable independent of the piston. The middle portion of each cylinder serves as the steam-chest for the other cylinder and contains a valve which is operated directly by the piston to control the flow of steam between the middle part of each cylinder and the ends of the associated cylinder.

In the drawings, Figure l is a side elevation of a duplex steam pump embodying my invention, the near steam-cylinder being shown in vertical longitudinal section. Fig. 2 is a central horizontal sectional view of the two steam-cylinders. Fig. 3 is alongitudinal vertical section of one steam-cylinder looking in the direction of the other. Figs. 4, 5, 6 and 7 are respectively sectional plan views on line 4, 5, 6, and 7, respectively, of Fig. 8. Fig. 8 is an end view of said cylinders. Fig. 9 is a transverse sectional view of the two cylinders, the section being taken in the plane indicated by line 9 of Fig. 2. Fig. 10 is a detached View of one of the pistons, showing the inner side of said pistonthat is to say, that side which is toward the other cylinder. Fig. 11 is a detached view of the other piston, showing the outer side thereof. Figs. 12, 13 and let are transverse sectional views, respectively,

in. the planes indicated by lines 12, 13, and 14:

of Fig. 10. Fig. 15 isa plan view of the valve and guide-arm in one cylinder. Fig. 16 is a 5 side elevation, partly broken away, of the part shown in Fig. 15.

The followingis adescription of the best embodiment of the invention now known to me:

Referring to the parts by letters, A and A represent two parallel steam-cylinders which are preferably formed in the same casting. The middle part of each cylinder is connected by two ports with each end of the other cylinder, these ports being formed, preferably, in the metal between the cylinders. In other words, there are eight ports of this characterto wit, the ports C, D, E and F, which connect the middle part of cylinder A with opposite ends of cylinder A, and the ports Cr, 5 H, I, and J, which connect the middle part of the cylinder A with opposite ends of the cylinder A. The ports C and E are inletports through which steam flows to opposite ends of cylinder A, and the ports D and F 7 are exhaust-ports through which steam flows from opposite ends of the cylinder A. The ports G and l are inlet-ports through which steam flows to opposite ends of cylinder A, and the ports H and J are exhaustports through which steam flows from opposite ends of cylinder A. The port-openings 0 (Z c f of the ports C, D, E, and F, respectively, in the middle part of the cylinder A are arranged in a transverse zone, being confined to an arc of about ninety degrees, including that part of the cylinder-wall which is nearest to the other cylinder. The port-open ngs at the opposite ends of these ports C, D, E, and F are found in the opposite ends of the other 5 cylinder, A, and are respectively indicated 0 and c (the inlet-port opening) and d and f, (the exhaust-port openings.) The port-openings g, It, i, and j of the ports G, H, I, and J are similarly arranged in the middle part of 9 cylinder A. The port-openings at the opposite ends of these ports in cylinder A are respectively indicated by g, i, it, and The inlet-port openings 0, g, e, and c" are placed near the ends of their respective cylinders, so that they will never be covered by the pistonheads. The outlet-port openings d, /t, f, and are placed at a greater distance from the ends of their respective cylinder and are placed in such positions that the piston-heads as they near the ends of the cylinders will cover said ports, and thereby imprison some steam in the cylinder ends, which steam being compressed acts to stop the piston and prevent it from striking the ends of the cylinder. In the metal between the two cylinders is a centrally-placed and longitudinallyextended final exhaust-port K, which communicates with both cylinders through the port-openings Zr; and 70, which are located in middle positions-that is to say, with two port-openings above and two below, as shown particularly in Figs. 3 and 9. Steam is admitted freely to the middle part of both cylinders through an initial inlet-port L, which is always open.

In the cylinders A and A are respectively the two pistons B and B, which are alike in the following respects, to wit: Each has two heads 6 and 7), which are fitted to the cylinder, and between them there is a body portion of smaller diameter than said heads, this body being preferably a hollow shell. The space between the piston-heads in each cylinder serves as a steam-chest for the other cylinder. In the body part of each piston and on that side thereof which is most remote from the other cylinder is a longitudinal slot Z), and directly opposite this slot there is an inclined slot 6, and in the body part of the piston is a recess U, with which both of said slots communicate. A guide-arm M in each cylinder is rigidly fastened to the wall thereof and projects through the slot 5" into the recess 6 and one of the purposes of this arm is to prevent the piston from turning-in other words, to compel it to move in an absolutely-straight line.

N N represent valves, of which there is one in each cylinder. Each has an arena] facefitting the curvature of the cylinder and is long enough to cover the group of five port-openings in the middle part of the cylinder in which it lies, and it does cover them all when in its middle position, as shown at the right of Fig. 9. It has a stem 02, which passes through the inclined slot 6 of the cylinder into the recess- 6 and lies between the bifurcated ends on of the arm M whereby it is prevented from moving endwise with the piston, but is thereby compelled by the inclined slot 7) to swing up and down as the piston moves to and fro. This valve contains the usual D-recess 02 which is adapted to establish communication between the final exhaust-port opening in and either of the exhaust-port openings above and below it. When the valveis in its lowest position, it is establishing communication between the final eXhaust-port opening and the exhaust-port below it. At this time the valve covers the lower inlet-port opening, but does not cover the upper inlet-port opening, and when the valve is moved to its upper position itopens the lower inlet-port opening and closes the upper inlet-port opening and the lower exhaust-port opening and establishes communication between the upper exhaust-port opening and the final exhaust-port opening k.

The mode of operation of the described mechanism will be understood from thefollowing description, which assumes the parts to start from the position shown in Figs. 2 and 9. The piston B is at the rear end of cylinder A, and piston B is in the middle of cylinder A and moving in the direction of the arrow. Steam is being freely admitted into both cylinders between the piston-heads 7) and I) through the port L, whereby the space between these two piston-heads in each cylinder serves as a steam-chest. Steam from the cylinder A is flowing through the upper port G to the front end of the cylinder A, thereby moving the piston B therein rearward. At the same time the exhaust-port J is connected with the port-opening it, which permits steam to flow to the final exhaust-port K from the front end of the cylinder A. All of the middle port-openings in cylinder A are closed; but a still further movement of the piston B will cause the valve N, associated with it, to move and to open up the port 0, so that steam will flow from the middle part of the cylinder A to the rear end of the cylinder A, at the same time establishing communication between the port K and the exhaust-port F, and consequently the piston B begins to move toward the front end of the cylinder A. The parts are so arranged that when either piston is at the middle of its path of travel the other piston is at one end or the other of its path. When the piston B reaches the middle of its path of travel, it has moved the valve so that all of the port-openings guarded by it are closed, the piston B having bythat time reached the rear end of cylinder A. A still further movement of this piston B moves the associated valve, so as to admit steam to the rear end of the cylinder A and to permit the fiow of steam to the front end of the same cylinder, whereupon piston B begins its rearward movement. These operations go on indefinitely. each piston moving the valve in its cylinder, which controls the flow of steam to and from the opposite cylinder.

It will be understood that in the particular embodiment of the invention shown the two inclined slots 1) in the two pistons are parallel when the parts are assembled, or otherwise the parts would not operate as described.

It will be understood, further, that it is not my desire or intention to be limited to any greater extent than is plainly expressed in the claims to the specific mechanism shown and herein described.v It is my desire, therefore, that my claims shall be construed to be. commensurate with the breadth of the invention and that they shall not be limited to any details beyond those which are plainly specified in the appended claims.

Having described my invention, I claim 1. In a steam-pump, the combination of two cylinders A A, each having an initial inletport, and a final outlet-port, and there being eight other ports which connect said cylinders, to wit; the inlet-ports C, E, which connect the middle part of cylinder A with the opposite ends of cylinder A, the inlet-ports G, I, which connect the middle part of cylinder A with opposite ends of A, all of the port-openings in the ends of said cylinders being close to said ends, two outlet-ports, D and F which connect the middle part of cylinder A with the opposite ends of cylinder A and the outlet-ports H and J which connect the middle part of cylinder A with the opposite ends of cylinder A, the port-openings of these outletports in the ends of the cylinders being at a considerable distance from said ends whereby they will be covered by the piston-heads as said heads near the ends of said cylinder, with a piston in each cylinder having two heads fitted to the cylinder and an intermediate body portion of smaller diameter, means preventing the rotation of said piston, sliding valve in each cylinder operable by the piston in an arcnalpath, and means preventing the longi- (tiudinal movement of the valve in said cylin- 2. In a pump, the combination of two cylinders, each provided with an initial inletport, a final outlet-port, four ports which lead from the middle part of each cylinder to opposite ends of the other cylinder, two inletport openings close tojopposite ends of the cylinder, and two outlet-port openings near opposite ends of the cylinder but at such a distance from said ends that they will be covered by the piston -heads when the piston nears the ends of the cylinder, all of the four port-openings last mentioned being in communication with the four ports which lead from the middle part of the other cylinder, with a piston having two heads, fitted to said cylinder and lying on opposite sides of the middle ports, and a connecting body portion of smaller diameter, means preventing the rotation of said piston, and avalve in the cylinder operable by the piston.

3. In a pump, the combination of two cylinders, each having an initial inlet-port, and

a final outlet-port, and ports connecting the middle part of each cylinder with the ends of the other cylinder, a piston in each cylinder consisting of two separated heads, fitted to the cylinder and lying at all times on opposite sides of said middle ports, and an intermediate body portion of smaller diameter, in which is a straight longitudinal slot, an inclined slot and an interior recess with which both slots communicate, a valve having a stem which extends through the inclined slot into said interior recess, an arm fixed to the inside of the cylinder and passing through the straight slot into said recess, and engaging with the stem of the valve, whereby said arm prevents the piston from turning and prevents the valve from moving lengthwise of the cylinder.

4. The combination of two cylinders each having an initial inlet-port communicating with the middle part thereof, and four ports leading from the middle part to the opposite ends of the other cylinder, and a final outletport for each cylinder, with a piston in each cylinder having a body portion and heads fitted to the cylinder lying on opposite sides of said port, and there being a straight slot in the one side of the body part of said piston, and an inclined slot in the opposite side of said piston, a fixed arm in the cylinder entering said straight slot, a valve in each cylinder having a stem which enters said inclined slot, and means preventing the endwise movement of said valve with its operating-piston.

5. The combination of two cylinders each having an initial inlet-port and four ports leading from it to the opposite ends of the other cylinder, and a final outlet-port for each cylinder, with a piston in each cylinder having a body portion and heads fitted to the cylinder lying on opposite sides of said ports, there being a straight slot and an inclined slot in the body part of said piston, a D-valve for each cylinder having a stem which enters said inclined slot, and a fixed arm which enters the straight slot and has a bifurcated inner end, which embraces the stem of said valve.

In testimony whereof I hereunto afiix my signature in the presence of two witnesses.

CLARENCE A. SNIDER.

W'itnesses:

E. B. GILoHRIsT, E. L. THURSTON. 

